Re: Add LSN along with offset to error messages reported for WAL file read/write/validate header failures

On Mon, Sep 19, 2022 at 07:26:57PM +0530, Bharath Rupireddy wrote:
> We have a bunch of messages [1] that have an offset, but not LSN in
> the error message. Firstly, is there an easiest way to figure out LSN
> from offset reported in the error messages? If not, is adding LSN to
> these messages along with offset a good idea? Of course, we can't just
> convert offset to LSN using XLogSegNoOffsetToRecPtr() and report, but
> something meaningful like reporting the LSN of the page that we are
> reading-in or writing-out etc.

It seems like you want the opposite of pg_walfile_name_offset().  Perhaps
we could add a function like pg_walfile_offset_lsn() that accepts a WAL
file name and byte offset and returns the LSN.

-- 
Nathan Bossart
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